Isolation Barrier

ABSTRACT

An apparatus and method for securing a tubular within another tubular or borehole, creating a seal across an annulus in a well bore, and centralising or anchoring tubing within a wellbore. A sleeve is arranged on a tubular body to create a chamber therebetween. A port provides fluid access through the body to the chamber. Each end of the sleeve is covered by a cylindrical portion of a connector. When fluid is introduced into the chamber the sleeve is morphed to secure it to a well bore wall and the ends of the sleeve are morphed to each cylindrical portion. The connection between the sleeve and body does not require a weld. The cylindrical portions may also be shrink fitted to the ends of the sleeves.

The present invention relates to an apparatus and method for securing a tubular within another tubular or borehole, creating a seal across an annulus in a well bore or centralising tubing within a wellbore. In particular, though not exclusively, the invention relates to morphing a sleeve to secure it to a well bore wall where the sleeve is connected to a supporting tubular body via a weld-less connection in which the sleeve is morphed to the connector, in use.

In the exploration and production of oil and gas wells, packers are typically used to isolate one section of a downhole annulus from another section of the downhole annulus. The annulus may be between tubular members, such as a liner, mandrel, production tubing and casing or between a tubular member, typically casing, and the wall of an open borehole. These packers are carried into the well on tubing and at the desired location, elastomeric seals are urged radially outwards or elastomeric bladders are inflated to cross the annulus and create a seal with the outer generally cylindrical structure i.e. another tubular member or the borehole wall. These elastomers have disadvantages, particularly when chemical injection techniques are used.

As a result, metal seals have been developed, where a tubular metal member is run in the well and at the desired location, an expander tool is run through the member. The expander tool typically has a forward cone with a body whose diameter is sized to the generally cylindrical structure so that the metal member is expanded to contact and seal against the cylindrical structure. These so-called expanded sleeves have an internal surface which, when expanded, is cylindrical and matches the profile of the expander tool. These sleeves work well in creating seals between tubular members but can have problems in sealing against the irregular surface of an open borehole.

The present applicants have developed a technology where a metal sleeve is forced radially outwardly by the use of fluid pressure acting directly on the sleeve. Sufficient hydraulic fluid pressure is applied to move the sleeve outwards and cause the sleeve to morph itself onto the generally cylindrical structure. The sleeve undergoes plastic deformation and, if morphed to a cylindrical metal structure, the metal structure will undergo elastic deformation to expand by a small percentage as contact is made. When the pressure is released the metal structure returns to its original dimensions and will create a seal against the plastically deformed sleeve.

During the morphing process, the inner surface of the sleeve will take up the shape of the surface of the wall of the cylindrical structure. This morphed isolation barrier is therefore ideally suited for creating a seal against an irregular borehole wall.

Such a morphed isolation barrier is disclosed in U.S. Pat. No. 7,306,033, which is incorporated herein by reference. An application of the morphed isolation barrier for FRAC operations is disclosed in US2012/0125619, which is incorporated herein by reference. Typically, the sleeve is mounted around a supporting tubular body, being fixed at each end of the sleeve to create a chamber between the inner surface of the sleeve and the outer surface of the body. A port is arranged through the body so that fluid can be pumped into the chamber from the throughbore of the body.

In use, the pressure of fluid in the throughbore is increased sufficiently to enter the chamber and force the sleeve outwardly to morph to the generally cylindrical structure. Sufficient pressure has been applied when there is no return of fluid up the annulus which verifies that a seal has been achieved.

In constructing such a barrier a tubular body is located coaxially within a sleeve member. The sleeve member is a steel cylinder being formed from typically 316L or Alloy 28 grade steel. The material of the sleeve is chosen so that it will undergo elastic and plastic deformation under fluid pressure. The sleeve member is therefore appreciably thin-walled of lower gauge than the tubular body and is preferably formed from a softer and/or more ductile material than that used for the tubular body. Each end of the sleeve member must be sealed to the outer surface of the tubular body so as to create the chamber. The connection between the tubular body and the sleeve must sufficiently secure the sleeve to the body so that they do not part under the influence of the fluid pressure. Additionally the connection must provide a pressure-tight seal so that the fluid pressure cannot escape through the joint.

A prior art connection for an isolation barrier is described in WO2010/0136806 and shown in cross-section in FIG. 1. The morphable sleeve A lies against casing B. The connection comprises an end nut C which is secured to the casing B by suitable means such as being locked thereto, etc. There is then provided a seal section housing D which is screwed fast to the end nut C and which surrounds a suitable arrangement of seals E which in use will prevent any fluid from exiting the chamber created when the sleeve A is expanded. The inner most ends of the respective seal section housings D are secured to the respective ends of the sleeve A by welding F. A weld shroud G is provided co-axially about the outer surface of the welding F and the respective end of the sleeve A and the inner most end of the sealed section housing D, where the weld shroud G is secured to the inner most end of the sealed section housing D via suitable screw threaded connection H but alternatively could be secured via welding (not shown). Accordingly, a portion of the inner surface or throughbore of the weld shroud G is in contact with and therefore lies over the outer surface of the weld F and thereby protects the weld F. More importantly though, the weld shroud G is formed from a very strong metal relative to the strength of the metal that forms the sleeve A and this provides the advantage that, when the sleeve A is expanded, the weld shroud G prevents the outer ends of the sleeve A and therefore the weld F from expanding.

WO2012/045813 describes a similar isolation barrier where the ends of the sleeve are sandwiched between parts, with the outer part being a cylindrical ring of a metal which is not as flexible as the metal of the expandable sleeve. Like the weld shroud of FIG. 1, this cylindrical ring prevents the ends of the sleeves expanding when fluid pressure is introduced to the chamber. In this arrangement, the expandable sleeve is also welded to the connection parts.

A disadvantage of the prior art is in the requirement to weld the expandable sleeve to a part of the connector. This would be a specialised weld as the two metals being welded together have differing chemical compositions. This adds to the cost of the barrier and prevents standard mechanical assembly of the barrier. Additionally, due to the stresses applied to the barrier during welding, requalification is required which causes delay and further costs.

It is therefore an object of at least one embodiment of the present invention to provide a morphed isolation barrier which obviates or mitigates one or more disadvantages of the prior art.

It is a further object of at least one embodiment of the present invention to provide a method of creating an isolation barrier in a well bore which obviates or mitigates one or more disadvantages of the prior art.

According to a first aspect of the present invention there is provided an assembly, comprising:

a tubular body arranged to be run in and secured within a larger diameter generally cylindrical structure; a sleeve member positioned around the exterior of the tubular body; first and second connectors at each end of the sleeve member to seal the sleeve member to the exterior of the tubular body and create a chamber therebetween; the tubular body including a port having a valve to permit the flow of fluid into the chamber to increase pressure within the chamber to cause the sleeve to move outwardly and morph against an inner surface of the larger diameter structure; characterised in that: each connector includes a cylindrical portion, the cylindrical portion locating over an end of the sleeve member, respectively; an inner surface of the cylindrical portion abutting an outer surface of the end of the sleeve member; an inner surface of the end of the sleeve member being spaced apart from an outer surface of the tubular body; and wherein fluid flow into the chamber acts on the inner surfaces of the ends of the sleeve members causing the sleeve ends to move outwardly and morph against the inner surfaces of the cylindrical portions.

In this way, welding is not required and the connection advantageously uses the fluid pressure already present to enhance the seal between the sleeve member and the connector.

Preferably there is an interference fit between the cylindrical portion and the end of the sleeve member. In this way a weld is avoided by initially shrink fitting the parts together.

Preferably the inner surface of the cylindrical portion is profiled. In this way the metal to metal seal between the cylindrical portion and the sleeve end is improved as the sleeve end is morphed into the profile.

Preferably, the profiled inner surface has one or more circumferentially arranged grooves. The recess of the groove may have a rectangular cross-section. In this way, the right-angled corners between the groove and the inner surface create a rim against which the metal to metal seal is formed and the sleeve end is morphed into a corrugated profile.

Optionally, the profiled inner surface may be formed by locating a plurality of rings against the inner surface of the cylindrical portion to provide the groove between adjacent rings. In this way, the inner surface of the cylindrical portion does not require machining.

Preferably, the connector includes a fluid exclusion member located in one or more grooves. In this way, a hydraulic lock is mitigated during morphing. The fluid exclusion member may comprise a crushable medium, such as, for example closed cell foam, such as, for example, metal foam or syntactic foam, placed in the recess in order to prevent fluid from filling the recess but being collapsible under the pressure of the end of the sleeve member as to allow the end of the sleeve member to enter the recess. The fluid exclusion member is also preferably capable of taking in some fluid whilst being collapsed thereby further minimising the risk of occurrence of a hydraulic lock.

In an embodiment, the first and the second connectors are affixed and sealed to the tubular body. In a preferred embodiment, the first connector is affixed to the tubular body and the second connector includes movement means to allow the second connector to move towards the first connector along the outer surface of the tubular body. In this way, the sleeve member is allowed to contract longitudinally during radial expansion to reduce thinning of the sleeve member during expansion.

Preferably the movement means comprises a sliding seal, the seal making contact with and sealing against the outer surface of the tubular body. In this way the chamber is always sealed.

Preferably the movement means comprises a ratchet. In this way, when the fluid pressure is released the second connector is fixed in position and the chamber is pressure-tight.

The large diameter structure may be an open hole borehole, a borehole lined with a casing or liner string which may be cemented in place downhole, or may be a pipeline within which another smaller diameter tubular section requires to be secured or centralised.

The tubular body is preferably located coaxially within the sleeve and is part of a tubular string used within a wellbore, run into an open or cased oil, gas or water well. Therefore the present invention allows a casing section or liner to be centralised within a borehole or another downhole underground or above ground pipe by provision of a morphable sleeve member positioned around the casing or liner. Centralisation occurs as the sleeve will expand radially outwardly at a uniform rate with the application of pressure through the port. Additionally, the present invention can be used to isolate one section of the downhole annulus from another section of the downhole annulus and thus can also be used to isolate one or more sections of downhole annulus from the production conduit.

Preferably the valve is a one-way check valve. In this way, fluid is prevented from exiting the chamber. More preferably the valve is set to close when the pressure in the chamber reaches the morphed pressure value. Advantageously, the valve includes a ruptureable barrier device, such as a burst disk device or the like. Preferably the barrier device is set to rupture at pressures around the morphed pressure value. In this way, fluids can be pumped down the tubing string into the well without fluids entering the sleeve until it is desirous to operate the sleeve.

According to a second aspect of the present invention there is provided a method of setting a morphed sleeve in a well bore, comprising the steps:

-   (a) locating a sleeve member in spaced apart relation around the     exterior of a tubular body; -   (b) locating first and second connectors at each end of the sleeve     member to seal the sleeve member to the exterior of the tubular body     and create a chamber therebetween; -   (c) running the tubular body on a tubular member into a wellbore and     positioning the sleeve member at a desired location within a larger     diameter structure; -   (d) pumping fluid through the tubular member and through a port in     the tubular body to access the chamber; -   (e) causing the sleeve member to move radially outwardly and morph     against an inner surface of the larger diameter structure; and -   (f) causing each end of the sleeve member to move radially outwardly     and morph against an inner surface of the first and second     connectors, respectively.

In this way, the fluid pressure used to morph the sleeve member against the larger diameter structure additionally assists in sealing the sleeve member to the connectors thus removing the requirement for welding.

Preferably, step (b) includes shrink fitting a portion of the connectors onto the ends of the sleeve member, respectively. In this way an interference fit is created which also does not require welding.

Step (e) may include morphing each end of the sleeve member against at least one recess on an inner surface of the first and second connectors, respectively. In this way the metal to metal seal between the sleeve member and the connectors is improved.

Step (e) may also include the step of excluding fluid from the at least one recess. In this way a hydraulic lock is avoided during morphing.

The large diameter structure may be an open hole borehole, a borehole lined with a casing or liner string which may be cemented in place downhole, or may be a pipeline within which another smaller diameter tubular section requires to be secured or centralised.

Preferably, the method includes the step of rupturing a disc at the valve to allow fluid to enter the chamber when the pressure reaches a desired value. This allows pumping of fluids into the well without fluid entering the sleeve member.

The method may include the steps of running in a hydraulic fluid delivery tool, creating a temporary seal above and below the port and injecting fluid from the tool into the chamber via the port. Such an arrangement allows selective operation of the sleeve member if more than one sleeve member is arranged in the well bore.

In the description that follows, the drawings are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce the desired results.

Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as “including,” “comprising,” “having,” “containing,” or “involving,” and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term “comprising” is considered synonymous with the terms “including” or “containing” for applicable legal purposes.

All numerical values in this disclosure are understood as being modified by “about”. All singular forms of elements, or any other components described herein including (without limitations) components of the apparatus are understood to include plural forms thereof.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings of which:

FIG. 1 is a cross-sectional view through a prior art connector of an assembly;

FIG. 2 is a cross-sectional view through an assembly according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view through a first connector of the assembly of FIG. 2;

FIG. 4 is a cross-sectional view through a second connector of the assembly of FIG. 2; and

FIGS. 5 a-5 c are schematic illustrations of a sequence for setting two sleeve members in an open borehole;

FIG. 5 a is a cross-sectional view of a liner provided with two sleeve members;

FIG. 5 b shows the liner in the borehole of FIG. 5 a with a hydraulic fluid delivery tool inserted therein; and

FIG. 5 c is a cross-sectional view of the liner of FIGS. 5 a and 5 b with morphed sleeves in accordance with the present invention, in use.

Reference is initially made to FIG. 2 of the drawings which illustrates an assembly, generally indicated by reference numeral 10, including a tubular body 12, sleeve member 14, chamber 16, port 18, first connector 20 and second connector 32 according to an embodiment of the present invention.

Tubular body 12 is a cylindrical tubular section having at a first end 22, a pin connector (not shown) and at an opposite end 26, a box connector (not shown) for connecting the body 12 into a tubing string such as casing, liner or production tubing that is intended to be permanently set or completed in a well bore. Body 12 includes a throughbore 30 which is co-linear with the throughbore of the string. The string may be a drill pipe or any other tubular string designed to be run in a well bore.

A port 18 is provided through the side wall 34 of the body 12 to provide a fluid passageway between the throughbore 30 and the outer surface 36 of the body 12. While only a single port 18 is shown, it will be appreciated that a set of ports may be provided. These ports may be equidistantly spaced around the circumference of the body 12 and/or be arranged along the body between the first end 22 and the second end 26 to access the chamber 16.

In an embodiment, at the port 18 there is located a check valve 54. The check valve 54 is a one-way valve which only permits fluid to pass from the throughbore 30 into the chamber 16. The check valve 54 can be made to close when the pressure within the chamber 16 reaches a predetermined level, this being defined as the morphed pressure value. Thus, when the pressure in the sleeve 14 reaches the morphed pressure value, the valve 54 will close. Also arranged at the port 18 is a rupture disc 56. The rupture disc 56 is rated to a desired pressure at which fluid access to the chamber is desired. In this way, the rupture disc 56 can be used to control when the setting of the sleeve 14 is to begin. The disc 56 can be operated by increasing pressure in the throughbore 30 with the pressure to rupture the disc being selected to be greater than the fluid pressure required to activate any other tools or functions in the well bore.

Tubular body 12 is located coaxially within a sleeve member 14. Sleeve member 14 is a steel cylinder being formed from typically 316L or Alloy 28 grade steel but could be any other suitable grade of steel or any other metal material or any other suitable material which undergoes elastic and plastic deformation. Ideally the material exhibits high ductility i.e. high strain before failure. The sleeve member 14 is appreciably thin-walled of lower gauge than the tubing body 12 and is preferably formed from a softer and/or more ductile material than that used for the tool body 12 and the connectors 20, 32. The sleeve member 14 may be provided with a non-uniform outer surface 40 such as ribbed, grooved or other keyed surface in order to increase the effectiveness of the seal created by the sleeve member 14 when secured within another casing section or borehole.

An elastomer or other deformable material may be bonded to the outer surface 40 of the sleeve 14; this may be as a single coating but is preferably a multiple of bands with gaps therebetween. The bands or coating may have a profile or profiles machined into them. The elastomer bands may be spaced such that when the sleeve 14 is being morphed the bands will contact the inside surface of the larger diameter structure e.g. casing or open borehole 80 first. The sleeve member 14 will continue to expand outwards into the spaces between the bands, thereby causing a corrugated effect on the sleeve member 14. These corrugations provide a great advantage in that they increase the stiffness of the sleeve member 14, increase its resistance to collapse forces and also improves annular sealing.

Sleeve member 14 is a cylindrical tube which surrounds the tubular body 12 and is spaced apart therefrom. The sleeve member 14 is not directly attached to any part, but it's radial movement is limited by connectors 20, 32 located at either end of the sleeve member 14.

Reference is now made to FIG. 3 of the drawings which illustrates a first connector, generally indicated by reference numeral 20, being an expanded view of the outlined section noted as element 20 in FIG. 2, of the assembly 10 according to a first embodiment of the present invention. Connector 20 joins the sleeve member 14 to the tubular body 12. Connector 20 comprises three sections 31, 33, 35 arranged longitudinally with the first end 38 of the connector being at section 31 and the second end 42 being at section 35. Second end 42 is arranged towards the first end 22 of the assembly 10. Section 31 is formed from a cylindrical portion 44 with an upper part 46, a mid-part 48 and a lower part 50. The upper part 46 provides an inner surface 52 against which a first end 60 of sleeve member 14 is located. In this way, the outer surface 40 of sleeve 14 abuts the inner surface 52 of the upper part 46 of cylindrical portion 44.

Upon the inner surface 52 of the upper part 46, there is located a recess 62. Recess 62 may take the form of a circumferential groove machined into the inner surface 52. While one recess 62 is illustrated in FIG. 3, there may be more than one located upon the inner surface. Recess 62 provides a pocket 64 into which the first end 60 of the sleeve member 14 can morph. In order to prevent fluid being trapped within the pocket 64 and preventing morphing of the first end 60 of the sleeve 14 into the groove 62. A fluid exclusion material may be located in the groove 62. Such a material would be a crushable medium such as a closed cell foam. This may be a metal foam or syntactic foam that is used to fill the void and prevent the capture of fluid during morphing but will crush and reduce the volume to allow entry of the sleeve end 60 into the recess 62 when the sleeve end 60 is morphed.

It is noted that the inner surface 66 of the sleeve 14 is spaced apart from the outer surface 36 of the tubular body 12. This spacing extends the chamber 16 to the distal end 68 of the sleeve member 14 and thus provides a route for fluid flow against the inner surface 66 of the sleeve end 60 for the purpose of morphing the sleeve end 60 against the cylindrical portion 44 and into the recess 62. The distal end 68 is arranged to abut a transverse face 70 of the upper part 46 of the connector 20. This provides a locator for the sleeve 14 in construction.

Transverse face 70 also marks the point where a lock-ring arrangement 72 is used to affix the connector 20 directly to the tubular body 12 as is known in the art. Adjacent to the lock-ring 72 a towards, the lower end 50 of the cylindrical portion 44, a sealing arrangement 74 is provided. Sealing arrangement 74 includes back-up rings bounding oppositely arranged chevron seals. These provide a seal to prevent fluid escaping from the chamber 16 through the connector 20. The sealing arrangement 74 and lock-ring arrangement 72 a are mounted on the mid-part 46 of the section 31. The lower part 50 of section 31 is then overlapped onto the mid-section 33 of the connector 20. The mid-section 33 includes feather keys 76 to further lock the connector 20 to the tubular body 12. The mid-section 33 is also overlapped by section 35 which contains a further lock-ring arrangement 72 b and an end nut in a similar manner as for the prior art connector shown in FIG. 1. Of note, is the absence of any weld in the connector there being only mechanical connections. This simplifies construction of the assembly as there is no requirement for any specialist welding or requalification of the connection as the connector is mechanically made up to the tubular body 12 of the sleeve 14 in position.

At a second opposite end 61 of the sleeve 14, there is provided a second connector 32. The second connector 32 is of similar design to the first connector 20 except that it includes a ratchet mechanism 73 and is absent any lock-ring arrangements 72. The ratchet arrangement 73 allows the connector 32 to move with the sleeve 14 towards a first end 22 during morphing of the sleeve when the sleeve 14 will naturally, longitudinally contract in the expansion process. In this way, the seal arrangement 74 within the connector 32 can move along the outer surface 36 of the tubular body 12. The ratchet arrangement 73 allows for movement in one direction only, that is, towards the first end 22. Thus, once morphing has been completed, the volume of the chamber 16 is fixed as the ratchet locks the position of connector 32 and with it, the transverse face 70 of connector 32 which defines one end of the chamber 16. As with connector 20, the second end 61 of the sleeve member 14 is spaced apart from the tubular body 12 so that fluid entering the chamber 16 can flow under the sleeve end 61 and morph the end 61 of the sleeve member 14 onto the inner surface 52 of the cylindrical portion 44 and preferentially, into the groove 62.

When the ends 60, 61 of the sleeve member 14 morph into the respective grooves 62, a corrugated shape is taken up by the ends 60, 61 of the sleeve member 14 which improves the sealing capability as the seal is made directly between the outer surface 40 of the sleeve member 14 and the corner 63 at the edge of the groove 62. This arrangement of grooves also increases the axial loading capacity through the sleeve and thus it improves the strength of the connection at the ends 60, 61 of the sleeve member 14 to the tubular body 12. Again, the second connector 32 includes no welded components and thus is purely of mechanical construction and thus, easy to assemble, and does not require any requalification of the assembly 10 following construction.

In use, the assembly 10 will be designed such that an outer diameter at the connectors 20, 32, is narrower than the diameter of the larger diameter cylindrical structure in which a barrier requires to be formed. This larger diameter cylindrical structure may be a casing or an open borehole. The sleeve member material is selected and sized to provide a morphed diameter which is equal to or greater than the diameter of the casing or open bore. Assembly 10 is formed by locating the first connector 20 upon the tubular body 12 and engaging the lock-ring 72 assemblies. Sleeve member 14 is then slid on over the second end 26 of the tubular body 12 and arranged coaxially with the tubular body 12 noting that the sleeve member 14 is spaced apart from the upper surface 36 of the tubular body 12. The sleeve member 14 is inserted into the cylindrical portion 44 until the distal end 68 meets the transverse face 70. At this position, the outer surface 40 of the first end 60 of the sleeve member 14 will lie against the inner surface 66 of the cylindrical portion 44. The cylindrical portion 44 is then shrink-fitted to the first end 60 of the sleeve member 14. This provides an interference fit between the connector 20 and the sleeve member 14. The second connector 32 is then located onto the body 12 at the second end 61 of the sleeve member 14 with the transverse face 70 abutting the distal end 68 of the sleeve member 14. Again, the second end 61 of the sleeve member 14 is spaced apart from the outer surface 36 of the tubular body 12. The ratchet arrangement 73 of connector 32 is positioned to allow movement of the connector 32 towards the sleeve member 14, but will initially be fixed in position holding the distal end 68 against the transverse face 70 at each end 60,61 of the sleeve member 14. Cylindrical portion 44 of connector 32 is also shrink-fitted to the second end 61 of the sleeve member 14 to provide an interference fit there-between. In this way, for initial assembly, the sleeve member 14 has an interference fit to the connectors 20, 32 and is sandwiched longitudinally between them. The arrangement provides a spaced-apart relationship between the sleeve member 14 and the tubular body 12 along the entire length of the sleeve member 14. Thus, the sleeve member 14 is not sandwiched radially between members as in all the prior art arrangements. It is further noted that there is no welding of the sleeve member 14 to any other part.

The first end 22 of the body 12 includes a pin section for connecting the assembly 10 into a tubular string such as a drill pipe as is known in the art. Similarly, the second end 26 includes a box section for similar connection into the tubular string. The tubular string is then run into a wellbore with the assembly 10 attached. When the assembly 10 has reached the desired location, fluid pressure is increased in the through-bore 30. The fluid is typically a fluid under pressure delivered from a pump at surface with a plug or stop located within the through-bore 30 at a position below the assembly 10 in the string. Pressure in the through-bore 30 thus increases to a point where the disc 56 is ruptured and allows fluid under pressure to pass through the check valve 54 at the port 18. As detailed previously, multiple ports 18 may be located upon the tubular body 12 to increase the rate of fluid pressure entering the chamber 16. On entry to the chamber 16, fluid will entirely fill the chamber including those portions at the first end 60 and second end 61 of the sleeve member 14. Indeed, the fluid will contact the transverse face 70 of respective connectors 20, 32. As the chamber 16 is cylindrical in nature and the material of the sleeve member 14 is more elastic than that of the tubular body 12, as pressure increases in the chamber 16, the sleeve member 14 will be forced radially outwardly from the tubular body across an annulus between the outer surface 36 of the tubular body 12 and an inner surface of the casing or open bore. During this expansion, the first and second ends 60, 61 of the sleeve member 14 will be equally forced radially outwardly from the tubular body 12, however, due to the interference fit to the upper part 46 of the cylindrical portion 44, they will morph against the inner surface 52 of the cylindrical portion 44 and into the groove 62 upon the inner surface 52.

Fluid pressure will continue to enter through port 18 until the sleeve member 14 contacts the inner surface of the casing or open bore hole and effectively morph the material of the sleeve member 14 against this surface. This morphing creates a metal-to-metal seal between the sleeve member 14 and the casing, if used. An identical morphing process occurs at the sleeve member end 60, 61 against the cylindrical portions 44 of the connectors 20, 32. This process is known and operates by elastically and then plastically deforming the sleeve member 14. Upon contact with the casing and the cylindrical portions 44 of the connectors 20, 32, these will also elastically deform under fluid pressure. At a morphed fluid pressure value, the check valve 54 closes therefore sealing the chamber 16. When the valve 54 is closed, the casing and the cylindrical portions 44 and the connectors 20, 32 will elastically relax back to their original diameters. This movement improves the metal to metal seal between the sleeve member 14 and the casing and also the connectors 20, 32. During expansion of the sleeve member 14, connector 32 may have moved towards the first end 22 of the body 12 as the sleeve member 14 longitudinally contracts to prevent the thinning of the sleeve member 14. Such movement is permitted via the ratchet arrangement 73 on the connector 32. However, at the point where the morphed pressure value is reached and the check valve 54 is closed, the ratchet arrangement 73 fixes the position of the connector 32 and thus, the size of the chamber 16. The seal between the assembly 10 and the casing or open bore hole thus forms a barrier in the wellbore so that fluid flow in the annulus between the two is prevented. Indeed, a loss of fluid flowing through the annulus can be considered as the point at which an effective barrier seal has been made by the assembly 10.

Reference will now be made to FIGS. 5 a-5 c of the drawings which provide an illustration of a further method for setting a sleeve within a well bore according to an embodiment of the present invention. Like parts to those in the earlier Figures have been given the same reference numerals to aid clarity.

In use, the assembly 10 is conveyed into the borehole by any suitable means, such as incorporating the assembly 10 into a casing or liner string 76 or on an end of a drill pipe and running the string into the wellbore 78 until it reaches the location within the open borehole 80 at which operation of the assembly 10 is intended. This location is normally within the borehole at a position where the sleeve 14 is to be expanded in order to, for example, isolate the section of borehole 80 b located above the sleeve 14 from that below 80 d in order to provide an isolation barrier between the zones 80 b, 80 d. Additionally a further assembly 10 b can be run on the same string 76 so that zonal isolation can be performed in a zone 80 b in order that an injection, frac'ing or stimulation operation can be performed on the formation 80 b located between the two sleeves 14, 14 b. This is as illustrated in FIG. 5B.

Each sleeve 14,14 b can be set by increasing the pump pressure in the throughbore 30 to a predetermined value which ruptures the disc 56 giving fluid access to the chamber 16. Fluid entering the chamber 16 increases in internal volume of the chamber 16, creating a pressure on the inner wall 46 sufficient to cause the sleeve 14 to move radially away from the body 12 by elastic expansion, contact the surface 82 of the borehole and morph to the surface 82 by plastic deformation.

Fluid may be pumped into the chamber 16 at any desired pressure as the check valve 54 can be set to allow a calculated volume of fluid which is sufficient to morph the sleeve to enter the chamber before closing. When closed, the check-valve will trap any fluid remaining in the chamber 16. Additionally, by locating a plug at any desired position in the string, such as the bottom of the string, fluid can be pumped from surface or from a tool located in the string to morph any desired number of sleeves, between the surface/tool and the plug, at the same time.

Each end of the sleeve member 60, 61 is sealed to the tubular body 12 via first and second connectors 20, 32. Each connector 60, 62 includes a cylindrical portion 44, the cylindrical portion 44 locating over an end 61, 61 of the sleeve member 14, respectively. An inner surface 52 of the cylindrical portion 44 abuts an outer surface 40 of the end of the sleeve member 60, 61 via an interference fit by shrink fitting. An inner surface 66 of the end of the sleeve member 60, 61 is spaced apart from an outer surface 36 of the tubular body 12. Fluid flow into the chamber 16 acts on the inner surfaces 66 of the ends of the sleeve members 60, 61 causing the sleeve ends to move radially outwardly and morph against the inner surfaces 52 of the cylindrical portions 44. Thus the fluid pressure used to morph the sleeve enhances the connection by creating a morphed metal-to-metal seal at each connector 20, 32.

The sleeve 14 will have taken up a fixed shape under plastic deformation with an inner surface 46 matching the profile of the surface 82 of the borehole 80, and an outer surface also matching the profile of the surface 82 to provide a seal which effectively isolates the annulus 84 of the borehole 80 above the sleeve 14 from the annulus 86 below the sleeve 14. If two sleeves 14,14 b are set together then zonal isolation can be achieved for the annulus 84 between the sleeves 14,14 b. At the same time the sleeves 14, 14 b have effectively centered, secured and anchored the tubing string 76 to the borehole 80. When the sleeves 14, 14 b are morphed, the ends 60, 61 will also have morphed so that the entire length of the sleeve member 14, 14 b is morphed radially outwardly.

An alternative method of achieving morphing of the sleeve 14 is shown in FIG. 5B. This method uses an activation fluid delivery tool 88. Once the string 76 reaches its intended location, tool 88 can be run into the string 76 from surface by means of a coiled tubing 90 or other suitable method. The tool 88 is provided with upper and lower seal means 92, which are operable to radially expand to seal against the inner surface 94 of the body 12 at a pair of spaced apart locations in order to isolate an internal portion of body 12 located between the seals 92; it should be noted that said isolated portion includes the fluid port 18. Tool 88 is also provided with an aperture 96 in fluid communication with the interior of the string 76.

To operate the tool 88, seal means 92 are actuated from the surface to isolate the portion of the tool body 12. Activation fluid is then pumped under pressure through the coiled tubing such that the pressurised fluid flows through tool aperture 96 and then via port 18 into chamber 16 and acts on the sleeve members 14,14 b in the same manner as described hereinbefore. Use of such a tool allows setting of selective assemblies 10 in a well bore.

A detailed description of the operation of such a fluid delivery tool 88 is described in GB2398312 in relation to the packer tool 112 shown in FIG. 27 of that patent with suitable modifications thereto, where the seal means 92 could be provided by suitably modified seal assemblies 214, 215 of GB2398312, the disclosure of which is incorporated herein by reference. The entire disclosure of GB2398312 is incorporated herein by reference.

Using either pumping method, the increase in pressure of fluid causes the sleeve 14 to move radially outwardly and seal against a portion of the inner circumference of the borehole 80 and the inner surfaces 52 of the connectors 20,32. The pressure within the chamber 16 continues to increase such that the sleeve 14 initially experiences elastic expansion followed by plastic deformation. The sleeve 14 expands radially outwardly beyond its yield point, undergoing plastic deformation until the sleeve 14 morphs against the surface 82 of the borehole 80 as shown in FIG. 5C. At the same time the sleeve ends 60, 61 will have morphed against the surfaces 52 of the connectors 20, 32 is an identical manner. Accordingly, the sleeve 14 has been plastically deformed and morphed by pressure from the chamber contents without any mechanical expansion means being required. Note that the connection is made to the sleeve without requiring a weld and is activated by the same fluid pressure used to create the barrier.

The principle advantage of the present invention is that it provides an assembly for creating an isolation barrier in a well bore which does not require a weld in its construction.

A further advantage of the present invention is that it provides an assembly for creating an isolation barrier in a well bore where the connection between and the tubular body is enhanced as the barrier is created using the same fluid pressure used to create the barrier.

It will be apparent to those skilled in the art that modifications may be made to the invention herein described without departing from the scope thereof. For example, while fluid pressure is used to morph the sleeve, the chamber may be filled with other expandable materials activated by the fluid to assist in the morphing process. 

1. An assembly, comprising: a tubular body arranged to be run in and secured within a larger diameter generally cylindrical structure; a sleeve member positioned around the exterior of the tubular body; first and second connectors at each end of the sleeve member to seal the sleeve member to the exterior of the tubular body and create a chamber therebetween; the tubular body including a port having a valve to permit the flow of fluid into the chamber to increase pressure within the chamber to cause the sleeve to move outwardly and morph against an inner surface of the larger diameter structure; characterised in that: each connector includes a cylindrical portion, the cylindrical portion locating over an end of the sleeve member, respectively; an inner surface of the cylindrical portion abutting an outer surface of the end of the sleeve member; an inner surface of the end of the sleeve member being spaced apart from an outer surface of the tubular body; and wherein fluid flow into the chamber acts on the inner surfaces of the ends of the sleeve members causing the sleeve ends to move outwardly and morph against the inner surfaces of the cylindrical portions.
 2. An assembly according to claim 1 wherein, there is an interference fit between the cylindrical portion and the end of the sleeve member.
 3. An assembly according to claim 1 wherein, the inner surface of the cylindrical portion is profiled.
 4. An assembly according to claim 3 wherein, the profiled inner surface has one or more circumferentially arranged grooves.
 5. An assembly according to claim 4 wherein, a recess of the groove has a rectangular cross-section.
 6. An assembly according to claim 3 wherein, the profiled inner surface is formed by locating a plurality of rings against the inner surface to provide a groove between adjacent rings.
 7. An assembly according to claim 4 wherein, the connector includes a fluid exclusion member located in the one or more grooves.
 8. An assembly according to claim 7 wherein, the fluid exclusion member comprises a crushable medium.
 9. An assembly according to claim 1 wherein, the first and the second connectors are affixed and sealed to the tubular body.
 10. An assembly according to claim 1 wherein, the first connector is affixed to the tubular body and the second connector includes movement means to allow the second connector to move towards the first connector along the outer surface of the tubular body.
 11. An assembly according to claim 10 wherein, the movement means comprises a sliding seal, the seal making contact with and sealing against the outer surface.
 12. An assembly according to claim 10 wherein, the movement means comprises a ratchet.
 13. An assembly according to claim 1 wherein, the large diameter structure is selected from a group comprising: an open hole borehole, a borehole lined with a casing or liner string, a borehole lined with a casing or liner string which is cemented in place downhole; a pipeline within which another smaller diameter tubular section requires to be secured or a pipeline within which another smaller diameter tubular section requires to be centralised.
 14. An assembly according to claim 1 wherein, the port includes a valve.
 15. An assembly according to claim 14 wherein, the valve is a one-way check valve.
 16. A method of setting a morphed sleeve in a well bore, comprising the steps: a) locating a sleeve member in spaced apart relation around the exterior of a tubular body; b) locating first and second connectors at each end of the sleeve member to seal the sleeve member to the exterior of the tubular body and create a chamber therebetween; c) running the tubular body on a tubular member into a wellbore and positioning the sleeve member at a desired location within a larger diameter structure; d) pumping fluid through the tubular member and through a port in the tubular body to access the chamber; e) causing the sleeve member to move radially outwardly and morph against an inner surface of the larger diameter structure; and f) causing each end of the sleeve member to move radially outwardly and morph against an inner surface of the first and second connectors, respectively.
 17. A method of setting a morphed sleeve in a well bore according to claim 16 wherein, step (b) includes shrink fitting a portion of the connectors onto the ends of the sleeve member, respectively.
 18. A method of setting a morphed sleeve in a well bore according to claim 16 wherein, step (e) includes morphing each end of the sleeve member against at least one recess on an inner surface of the first and second connectors, respectively.
 19. A method of setting a morphed sleeve in a well bore according to claim 18 wherein, step (e) includes the step of excluding fluid from the at least one recess.
 20. A method of setting a morphed sleeve in a well bore according to claim 16 wherein the method includes the steps of running in an activation fluid delivery tool, creating a temporary seal above and below the port and injecting fluid from the tool into the chamber via the port. 